History is the repeating story of the White race building great Civilizations and pushing Humanity forwards, only to import other races and miscegenerate with them - whereupon the Civilization crumbles and destroys itself.
History is the study of the past, not a particular race. Claiming that "white" civilization is more important than others is blatant Eurocentrism. Claiming that miscegenation caused their downfall is grossly overlooking social, political, religious, and historically contextual factors.
Greek Civilization was White run by White people. Egypt was ruled by White people with the Nubian and Semitic races as a minority under rule - this continued until miscegeneration became the norm in both cultures.
Egyptian text: "Southern boundary, made in the year 8, under the majesty of the king of Upper and Lower Egypt, Sesostris III, ... in order to prevent that any Black should cross it, by water or by land, with a ship, or any herds of the Blacks; except a Black who shall come to do trading in Iken, or with a commission. Every good thing shall be done with them but without allowing a ship of the Blacks to pass by Heh, going down stream, forever."
Viewed another way, history is the story of one privileged race with better access to resources ambushing every other race with war, raping and enslaving everyone in their path, and viewing themselves as genetically superior based purely on arrogance.